A legeltetés hatása a gyepekre és természetvédelmi vonatkozásai a Tapolcai- és a Káli- medencében

A Tapolcai- és a Káli-medence gyepterületein (Badacsonytomaj, Nemesgulács, Kisapáti, Gyulakeszi, Káptalantóti, Kővágóörs, Köveskál) végeztünk botanikai vizsgálatokat, valamint termésbecslést. A cönológiai felvételeket a növények fajszáma, összborítása, a gyógy- és mérgező fajok száma, a relatív talajnedvesség, relatív nitrogénigény és takarmányozási mutatók alapján értékeltük. A termésbecslés alapján kiszámítottuk a területre terhelhető állatlétszámot és azt összehasonlítottuk a jelenleg ott legelő létszámmal. A vizsgált medencékben a legelterjedtebb hasznosítási mód a szabad legeltetés. Gyepjeikre általában jellemző volt a kedvezőtlen fajösszetétel, melynek kialakulása rendszerint visszavezethető a rossz gazdálkodási stratégiára, a felhagyott területek nagy arányára, mely kiváló lehetőség a ruderális fajok felszaporodására

High resolution vegetation assessment with beta-diversity - a moving window approach

Monitoring designs are often suffering from the inherent non-stationarity of the monitored systems. To overcome this limition, we propose a sampling designs based on high resolution mapping and spatial analyses with double spatial scaling process. Applying for vegetation, we record the presence of plant species along 26 m or 52 m long belt transects of 520 (or 1040) units of 0.5 cm x 0.5 cm contiguous microquadrats. Beta diversity (represented as the diversity of species combinations) is estimated by subsequent computerised samplings from the baseline transect data sets. Beta diversity is scaled with changing resolutions across a range of scales from 5 cm x 5 cm to 5 cm x 500 cm. Second, it is also scaled using moving window. Local maximum of beta diversity is repeatedly calculated in 5 m extent observational windows shifted along the transect with 1 m lag, and the spatial variability of vegetation is visualized by the related beta-diversity profile. Using field example, we demonstrate that beta diversity, when applied with our methodology, is a sensitive indicator, and it can reveal more information than alpha or gamma diversity.</jats:p

Comparative study on grasslands dominated by Festuca vaginata and F-pseudovaginata in the Carpathian Basin

The aim of our study was to reveal the differences in the species composition and soil properties of open sandy grasslands dominated by different Festuca species, Festuca vaginata and F. pseudovaginata. Due to the arid conditions, sandy grasslands are generally covered by xerothermic vegetation in which F. vaginata is a typical dominant species. Festuca pseudovaginata, a species newly described by the authors, can also gain dominance in sandy grasslands. However, species composition and soil properties of grasslands dominated by this recently discovered species are still undiscovered. Based on previous coenological studies, we hypothesised that the grasslands characterised by the endemic F. vaginata are more species-rich than those with F.pseudovaginata. Coenological sampling was carried out in May 2009 at two study sites using the Braun-Blanquet method in quadrats of 2 m x 2 m. Five releves were sampled in stands dominated by F. vaginata and F. pseudovaginata respectively at two study sites in Central Hungary, resulting in a total of twenty releves. Analyses were based on the cover scores of vascular plant species and cryptogam crust and values of seven soil properties (pH [KC1], pH [H2O], humus, total N, Ca, P2O5 and K2O) measured in the 0-15 and 15-30 cm soil layers. Soil properties of the grasslands dominated by F. pseudovaginata and F. vaginata (dependent variables) were compared by linear mixed models, where 'grassland type' was the fixed factor and 'site nested in grassland type' was considered as random factor. Data were analysed by cluster analysis, fusion algorithm was a combinatorial method (minimising increase of variance), and the correlation was used as comparative function. We compared the cover of subordinate species by Mann-Whitney U test. We found that F. pseudovaginata and F. vaginata samples were well separated, and grasslands dominated by F. pseudovaginata had nearly two times more species than those dominated by F. vaginata. Based on the cluster analyses using plant cover and upper 0-15 cm soil layer data, F. pseudovaginata and F. vaginata groups could be well separated. Linear mixed models revealed that F. vaginata grass-lands were typical on soils with higher pH, nitrogen, phosphorous and potassium contents compared to F. pseudovaginata grasslands, which indicates a tight connection between the properties of the upper soil layer and the vegetation in sandy grasslands